Engine is one of the most important and costliest part/system of a vehicle, which acts like a heart of the human being, so, we have to keep it in always good condition.I t consumes around 55% of operating cost of the vehicle, due to which we have to concentrate more on it to r educe the oper ating cost and to improve the efficiency. perfor mance and long life of the engine. 1. Air intake system. 2. Cooling system. 3. Lubr ication system. 4. Fuel injection system. Service indicator is provided on air filter to indicate the blockage in the air filter. Ther e is a red band can be seen fr om the tr ansparent side of the indicator when blockage takes place. When th r ed band is seen in service indicator , reset the service indicator by pressing down the black cap. Star t the engine and if the red band is seen again then replace the primar y cartridge. Procedure foe checking & replacement air filter car tridge: